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太阳系行星及行星际大气环境特性研究 被引量:8
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作者 达道安 杨亚天 涂建辉 《宇航学报》 EI CAS CSCD 北大核心 2006年第6期1306-1313,共8页
研究了行星及行星际大气环境特性。为了克服用玻耳兹曼公式(BF)计算行星大气总分子数时出现的发散困难,在玻耳兹曼公式中引入新的归一化函数g(r),得到了新的行星大气分布律公式(RBF),探讨了归一化函数的物理意义。和Jeans的理论进行了... 研究了行星及行星际大气环境特性。为了克服用玻耳兹曼公式(BF)计算行星大气总分子数时出现的发散困难,在玻耳兹曼公式中引入新的归一化函数g(r),得到了新的行星大气分布律公式(RBF),探讨了归一化函数的物理意义。和Jeans的理论进行了比较。用RBF计算了太阳系中木星、土星、天王星、海王星和土卫六的大气密度随高度的分布。这些结果对于开展行星探测工作有一定的指导意义。 展开更多
关键词 行星大气 空间分布律 逃逸方程 大气寿命 火星 水汽
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太阳系类地行星际真空环境特性研究 被引量:3
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作者 达道安 杨亚天 涂建辉 《真空科学与技术学报》 EI CAS CSCD 北大核心 2005年第z1期1-8,共8页
用玻耳兹曼公式(BF)计算行星表面气体压力随高度的变化,取得了满意的结果.但用BF计算行星表面大气总分子数,则给出了发散的结果.对BF重新进行归一化,引入一个与距离r,温度T有关的归一化因子g(r),得到了新的行星大气分布律公式(RBF).由RB... 用玻耳兹曼公式(BF)计算行星表面气体压力随高度的变化,取得了满意的结果.但用BF计算行星表面大气总分子数,则给出了发散的结果.对BF重新进行归一化,引入一个与距离r,温度T有关的归一化因子g(r),得到了新的行星大气分布律公式(RBF).由RBF得出了地球大气总量与大气压力的关系式、行星大气层内大气总质量和高度的关系式、行星大气压力和高度的关系式以及行星大气温度与大气压力的关系.其计算值与实测结果符合性好.在行星表面附近,RBF的计算值与BF一致.本文利用RBF公式,计算了地球、金星、火星等类地行星际的大气密度分布及火星水汽的寿命. 展开更多
关键词 行星大气 空间分布律 地球大气 归一化因子 金星 火星
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Gully Erosion Regionalization of Black Soil Area in Northeastern China 被引量:13
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作者 YANG Jiuchun ZHANG Shuwen +3 位作者 CHANG Liping LI Fei LI Tianqi GAO Yan 《Chinese Geographical Science》 SCIE CSCD 2017年第1期78-87,共10页
Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fe... Gully erosion is the frequent and main form of soil erosion in the black soil area of the northeastern China, which is one of the most important commodity grain production bases in China. It is encroaching upon the fertile farmland there. Regionalization of gully erosion can reveal the spatial distribution and regularity of the development of gully erosion. Based on the eco-geographical regional background features of the black soil area, this study combined the regionalization with influencing factors of the development of gully erosion. GIS spatial analysis, geostatistical analysis, spatial statistics, reclassification, debris polygon processing and map algebra methods were employed. As a result, the black soil area was divided into 12 subregions. The field survey data on type, length, volume and other characteristics indicators of gully erosion were used to calibrate the results. Then the features of every subregion, such as where the gully erosion is, how serious it is, and why it happens and develops, were expounded. The result is not only an essential prerequisite for gully erosion surveys and monitoring, but also an important basis for gully erosion prevention. 展开更多
关键词 regionalization gully erosion soil and water conservation black soil area northeastern China
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Spatial Distribution of Mulberry Thrips,Pseudodendrothrips mori Niwa (Thysanoptera:Thripidae) 被引量:5
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作者 Shahram Hesami Kayvan Etebari +1 位作者 Hassan Pourbabaei Mohammad Mojtaba Kamelmanesh 《Zoological Research》 CAS CSCD 北大核心 2007年第3期265-270,共6页
Pseudodendrothrips mori is a serious pest to mulberry trees and its infestation affects the qualitative and quantitative characteristics of mulberry leaves consumed by silkworm. The spatial distribution of mulberry th... Pseudodendrothrips mori is a serious pest to mulberry trees and its infestation affects the qualitative and quantitative characteristics of mulberry leaves consumed by silkworm. The spatial distribution of mulberry thrips within plant and orchard was assessed using Taylor's power law and Morisita's index of dispersion. The results showed that P.mori populations were localized in certain parts of the trees and fields. Distribution of thrips within plant showed that the larval instars were located on lower canopy (leaves 5-10 from top) of trees but adults preferred the upper canopy (leaves 1-5 from top). The thrips density did not vary significantly among the leaf direction inside the trees. The thrips tended to be more accumulated on the trees located in East, South and North than in Center and West of orchard. The distributions of P.mori adults and larvae on the leaves were aggregated. 展开更多
关键词 Mulberry thrips Pseudodendrothrips mori spatial distribution Taylor's power law Iran
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Experimental analysis on bolt interference during advanced water detection with the mine transient electromagnetic method 被引量:2
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作者 Xiong-Wu HU Ping-Song ZHANG +1 位作者 Jia-Ping YAN Pei-Gen LI 《Journal of Coal Science & Engineering(China)》 2013年第3期407-413,共7页
During advanced water detection using the transient electromagnetic method, the exploration effect for water-rich area is often poor due to the interference of bolts that are distributed in different positions in work... During advanced water detection using the transient electromagnetic method, the exploration effect for water-rich area is often poor due to the interference of bolts that are distributed in different positions in working face. Thus, the study on the interference characteristics of bolts in different states has important directive significance for improving the acquisition quality and data processing method in water detection. Based on the analysis of the distribution laws of magnetic field excited by small multi-turn coincident loop in full space of homogeneity, the test on the interference of bolts has been designed in the mine. Through drilling 18 holes around the overlapping coil in the working face, mass data are collected in order with the posi- tion change and the exposed bolt length. The results of comprehensive data analysis show that the transient electromagnetic field is strongly interfered as the distance between the bolt and the center of the coil is less than 3 m, and the interference varies greatly as the distance varies. On the other hand, the field induced by the bolts can be ignored as the distance exceeds 3 m. The findings can help to improve data acquisition and correction during advanced water detection when using the transient electromagnetic method. 展开更多
关键词 mine transient electromagnet advanced detection mine testing ground bolt interference attribute
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The study of the law of the space density distribution of Ag-Ultrafine particles
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作者 DengZhaojing LiangYiping +1 位作者 LiJian RenHongxiang 《西南师范大学学报(自然科学版)》 CAS CSCD 1994年第4期371-377,共7页
ThestudyonthespacedensitydistributionofAg-UltrafineparticlesDengZhaojing,LiangYiping,LiJian,RenHongxiang(Dep... ThestudyonthespacedensitydistributionofAg-UltrafineparticlesDengZhaojing,LiangYiping,LiJian,RenHongxiang(DepartmentofPhysics,... 展开更多
关键词 银超微粒 空间密度分布
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Spatial distribution rules and affecting factors of BIF in Anshan-Benxi area
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作者 WANG Wenqi ZHANG Wei +2 位作者 PENG Chong ZHU Ming XUE Linfu 《Global Geology》 2015年第2期109-116,121,共9页
A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the ... A detailed investigation on 3D spatial distribution rules of Banded Iron-bearing Formation(BIF) with methods of gravity-magnetic inversion and 3D modeling of iron mine is presented based on the former analysis in the Anshan-Benxi area.Three dimension spatial distribution types of BIF are concluded as hook-like,tabularlike and "W"-like.BIF was mainly developed in three types of space including(1) the syncline cores,(2)cover coverage area,and(3) the deeper buried area where the range of tectonic uplift is small.The influences of tectonism,magmatic intrusion and uplift-erosion on the spatial distribution shapes of BIF are clarified. 展开更多
关键词 Anshan-Benxi area BIF geometric types iron ore bodies affecting factors
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